Shilajit is the most important drug of Ayurvedic and folk- medicine systems.
In the raw form it is a bituminous substance, which is a compact mass of vegetable
organic matter composed of dark red gummy matrix. It is bitter in taste, and
its smell resembles cow's stale urine. The botanical name of Shilajit is Asphaltum
(mineral pitch).

In the Ayurvedic texts it is called as silajatu or shilajatu,
but is commonly known as Shilajit. Its Sanskrit meaning is "conqueror
of mountains and destroyer of weakness." Several other terms like dhaturas,
dhatusara, shiladhatu, etc. also have been used for it in ancient
medical texts like Sushruta Samhita, Charak Samhita, Rasarangini,
etc. The term dhau, which was used as synonyms of Shilajit like dhahurasa,
dhahusara etc., was simply to emphasise its potentialities as rarayana,
which increases the activities of the saptadhatus of the body.

Shilajit usually collected over the ground or is found flowing out from between
fissures in the rocks in summer months due to strong heat of the sun. In India,
it is found in the romantic surroundings of the Himalayas: from Arunachal
Pradesh in the east to Kashmir in the west. It is also found in Afghanistan,
Bhutan, China, Nepal, Pakistan, Tibet, and Norway, where it is collected in
small quantities from steep rock faces at altitudes between 1000 and 5000
m. Shilajit samples from different region of the world have different physiological
properties.

Shilajit in Ayurveda

In the Charak Samhita, Shilajit is described as a product of four
minerals: gold, silver, copper and iron, whereas Susruta Samhita included
two more minerals, lead and zinc in its composition. According to the predominance
of the minerals of the source rock, it was classified into four categories:
Sauvarna, Rajat, Tamra and Lauha. The last variety
Lauha shilajit or blackish-brown Shilajit is common and is supposed
to be most effective. Charaka Samhita mentions that without the aid
of Shilajit no curable disease can be alleviated.

According to Susruta Samhita 15,32-40, that obesity can be cured by
taking enemas of drugs with liquefying properties which contain minerals like
Silajatu, cow's urine, the three myrobalans, honey, barley etc. Traditionally
people use it with pure milk to enhance energy, sexual and spiritual power.

Origin of Shilajit

Many researchers claim that Shilajit exuding from the rocks of mountains
is basically derived from vegetative source. Several shlokas of Susruta
Samhita and Rasarangini also maintain this point of view. According
to Sushruta, in the months of May-June the sap or juice of plants comes
out as gummy exudation from the rocks of mountains due to strong heat of sun
and Rasarangini, Dwarishtarang also claim that the Shilajit
is an exudation of latex gum-resin etc. of plants which comes from the rocks
of mountains in presence of scorching heat. But the exact source of the origin
of Shilajit is still under controversy.

There are several hypotheses regarding the origin of Shilajit:

Early work on Shilajit showed that it is mainly composed
of humus- the characteristic constituent of soils- together with other organic
components.

Some workers think that Euphorbia royleana Boiss.
plants are responsible for origin of Shilajit, because this plant is very
rich latex.

The chemical analysis of Shilajit by researchers at Bananas
Hindu University in India revealed that humification of some resin/latex
bearing plants is the most likely source of Shilajit.

The recent discoveries suggest that the humification of
resin-bearing plants was responsible for the major organic mass of Shilajit.
And chemical analysis showed that about 80% of the humus components are
present in Shilajit.

Another recent research claims that the mosses like species
of Barbula, Fissidenc, Minium, Thuidium and
species of Liverworts like Asterella, Dumortiera, Marchantia,
Pellia, Plagiochasma and Stephenrencella-Anthoceros
were present in the vicinity of Shilajit exuding rocks and these bryophytes
are responsible for formation of Shilajit. The bryophytes reveal occurrence
of minerals and metals in their tissue such as copper, silver, zinc, iron,
lead etc, which are similar to the elements present in Shilajit.

The composition of Shilajit is influenced by factors such
as the plant-species involved, the geological nature of the rock, local
temperature profiles, humidity and altitude.

Shilajit and Health

Shilajit is most important drug for many diseases. It was used as a drug
in prehistoric periods. There is evidence of Shilajit (Silajatu) in
the Indus civilization. Traditionally it is used as power increasing tonic.
The following health properties are found in Shilajit:

Promotes the movement of minerals, especially calcium,
phosphorous, and magnesium into muscle tissue and bone.

Stimulates the immune system and improves restoration
(recovery) after exercise.

Increases levels of growth hormone in diabetic patients
and is a potent anti-ulcer agent.

Conclusion

Shilajit is a humus rich blackish-brown substance, which is very useful in
many diseases and serves as a potent tonic. But its source of origin is still
under controversy. Traditionally it is also considered to increase virility,
cure diabetes, and in Ayurvedic medicine system of India, it is used against
various diseases.